=========================================================================Ubuntu Security Notice USN-2824-1
December 01, 2015

linux-lts-utopic vulnerability
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 14.04 LTS

Summary:

The system could be made to crash under certain conditions.

Software Description:
- linux-lts-utopic: Linux hardware enablement kernel from Utopic

Details:

Dmitry Vyukov discovered that the Linux kernel's keyring handler attempted
to garbage collect incompletely instantiated keys. A local unprivileged
attacker could use this to cause a denial of service (system crash).

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 14.04 LTS:
  linux-image-3.16.0-55-generic   3.16.0-55.74~14.04.1
  linux-image-3.16.0-55-generic-lpae  3.16.0-55.74~14.04.1
  linux-image-3.16.0-55-lowlatency  3.16.0-55.74~14.04.1
  linux-image-3.16.0-55-powerpc-e500mc  3.16.0-55.74~14.04.1
  linux-image-3.16.0-55-powerpc-smp  3.16.0-55.74~14.04.1
  linux-image-3.16.0-55-powerpc64-emb  3.16.0-55.74~14.04.1
  linux-image-3.16.0-55-powerpc64-smp  3.16.0-55.74~14.04.1

After a standard system update you need to reboot your computer to make
all the necessary changes.

ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed. If
you use linux-restricted-modules, you have to update that package as
well to get modules which work with the new kernel version. Unless you
manually uninstalled the standard kernel metapackages (e.g. linux-generic,
linux-server, linux-powerpc), a standard system upgrade will automatically
perform this as well.

References:
  https://ubuntu.com/security/notices/USN-2824-1
  CVE-2015-7872

Package Information:
  https://launchpad.net/ubuntu/+source/linux-lts-utopic/3.16.0-55.74~14.04.1